The flavor of the composite pseudo-goldstone Higgs

By Csaba Csáki, A. Falkowski, A. Weiler. 2008

302 citations recorded by the source corpus.

We study the flavor structure of 5D warped models that provide a dual description of a composite pseudo-Goldstone Higgs. We first carefully re-examine the flavor constraints on the mass scale of new physics in the standard Randall-Sundrum-type scenarios, and find that the KK gluon mass should generically be heavier than about 21 TeV. We then compare the flavor structure of the composite Higgs models to those in the RS model. We find new contributions to flavor violation, which while still are suppressed by the RS-GIM mechanism, will enhance the amplitudes of flavor violations. In particular, there is a kinetic mixing term among the SM fields which (although parametrically not enhanced) will make the flavor bounds even more stringent than in RS. This together with the fact that in the pseudo-Goldstone scenario Yukawa couplings are set by a gauge coupling implies the KK gluon mass to be at least about 33 TeV. For both the RS and the composite Higgs models the flavor bounds could be stronger or weaker depending on the assumption on the value of the gluon boundary kinetic term. These strong bounds seem to imply that the fully anarchic approach to flavor in warped extra dimensions is implausible, and there have to be at least some partial flavor symmetries appearing that eliminate part of the sources for flavor violation. We also present complete expressions for the radiatively generated Higgs potential of various 5D implementations of the composite Higgs model, and comment on the 1–5 percent level tuning needed in the top sector to achieve a phenomenologically acceptable vacuum state.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e9ba9324209c41178da39547b50970fc8bb3ed7e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. M. Redi
2. A. Wulzer
3. Andrea Tesi
4. G. Panico
5. A. Weiler
6. Andrzej Buras
7. R. Rattazzi
8. O. Matsedonskyi

In Nuclear and High Energy Physics

1. Andrzej Buras
2. David M. Straub
3. A. Wulzer
4. G. Panico
5. T. Hurth
6. Stefania Gori
7. M. Redi
8. Andrea Tesi

Citations in the corpus

• A Model of Lepton Masses from a Warped Extra Dimension (2008, methodology): “In fact, Kitano [19] showed that a bound of mKK > 25 TeV applies in this case.”
• A first top partner hunter’s guide (2012, background): “This is because of constraints from K [5], electric dipole moments and lepton flavor violation (see ref.”
• Higgs-mediated FCNCs: natural flavour conservation vs. minimal flavour violation (2010, unknown): “For instance, in models with warped space-time geometry [27, 28 ] or, equivalently, models with partial compositeness [29], or hierarchical fermion wave functions [30], we expect”
• Flavor and CP invariant composite Higgs models (2011, methodology): “For example, the Wilson coefficient C4 of LR 4-Fermi operators q̄ iα R q j Lαq̄ iβ L q j Rβ is suppressed by [8], ∼ 1 m(2)ρ g2 ρ Y 2 U,D 2mimj v2 (2.”
• Flavor Physics in the Quark Sector (2009, background): “It turns out then that the otherwise so powerful RS-GIM mechanism in this case is not sufficient to suppress the new physics contribution below the experimental limits, so that assuming completely anarchic 5d Yukawa couplings a lower bound on the KK mass scaleMKK ≃ 20TeV is obtained [182,1221].”
• Electroweak and Flavour Structure of a Warped Extra Dimension with Custodial Protection (2009, background): “In this case it turns out [26] that while the flavour structure remains unchanged at the qualitative level, an enhancement of flavour violating effects appears, leading to somewhat more stringent phenomenological constraints.”
• On the tuning and the mass of the composite Higgs (2012, methodology): “This has been verified explicitly in 5d holographic models [8, 9, 10] and explained parametrically in Ref.”
• Composite leptoquarks and anomalies in B-meson decays (2014, background): “Various non-anarchic flavour structures have been considered in the context of partial compositeness, see for example [42, 70–76].”
• Rare K and B Decays in a warped extra dimension with custodial protection (2008, methodology): “ns of ZH,Z′ and A(1). We note that the strength of RS flavour violation depends on the presence of possible brane kinetic terms which alter the matching relation between 5D and 4D gauge couplings, see [1,16,29] for details. In order not to complicate the present analysis we assume the simple intermed”
• ΔF = 2 observables and fine-tuning in a warped extra dimension with custodial protection (2008, methodology): “The UV brane terms consist of a possible (positive) bare kinetic term and an always present negative term [13, 32–38], which is due to the asymptotically free QCD running from the Planck scale to the TeV scale, see [18] for an extended discussion.”
• Electroweak constraints on flavorful effective theories (2015, background): “from 4-quark operators induced by heavy gluon exchange [63].”